[MPlayer-dev-eng] [DOCS] encoding.html

[D Richard Felker III]

On Mon, Nov 04, 2002 at 09:47:29AM +0100, Winner of tha face compo wrote:
> > - encoding tutorial
> Ok (who knows general rules about encoding?:))
> We shouldn't try to cover too much area because the DOCS gets too big, and
> each movie must be encoded in different ways. And it is too short, users
> will come asking us questions.. What is the ideal way?

A few essential tips...

The #1 thing to stress is to always crop black borders entirely! Even
leaving a couple pixels will mess up ME and complicate the DCT
coefficients horribly.

#2, Space will be wasted unless movie dimensions are a multiple of 16,
so scale or crop to a good size!

#3, If you get ugly mpeg artifacts encoding at the desired bitrate,
you need to reduce the complexity of the scene before encoding.
Applying a mild gaussian blur with the scale or unsharp filters can
help quite a bit (find good default/example params to include in
tutorial). It may also be a good idea to turn on single coefficient
elimination and luma/dark masking in lavc.

#4, if the movie is black and white you can save a little space and
time by encoding with -lavcopts gray.

There are lots more too, but these are some of the important ones,
IMO.

> > Also, I want to collect people to write these sections.
> lol :))

I'd be happy to help with some of it, if I have time.

> > I myself subscribing for video filters, unless someone else wants it :)
> Yes, do it if you want. (you can:)

Don't describe filters in detail again (that would duplicate manpage);
instead, explain how to use them effectively for better encoding.

> > I need help especially for the tutorial section (tips, recommendations for
> > bitrates/sizes etc) and for detailed codec parameters (effect,
> > advantages/disadvantages of encoding modes, B frames, various options etc).
> I can't, I don't know them either...

I know a bit about this stuff, so I could probably provide advice.

Rich